Effects of Nanoparticle Size on Cellular Uptake and Liver MRI with Polyvinylpyrrolidone-Coated Iron Oxide Nanoparticles Jing Huang Lihong Bu Jin Xie Kai Chen Zhen Cheng Xingguo Li Xiaoyuan Chen 10.1021/nn101643u.s001 https://acs.figshare.com/articles/journal_contribution/Effects_of_Nanoparticle_Size_on_Cellular_Uptake_and_Liver_MRI_with_Polyvinylpyrrolidone_Coated_Iron_Oxide_Nanoparticles/2702137 The effect of nanoparticle size (30−120 nm) on magnetic resonance imaging (MRI) of hepatic lesions <i>in vivo</i> has been systematically examined using polyvinylpyrrolidone (PVP)-coated iron oxide nanoparticles (PVP-IOs). Such biocompatible PVP-IOs with different sizes were synthesized by a simple one-pot pyrolysis method. These PVP-IOs exhibited good crystallinity and high <i>T</i><sub>2</sub> relaxivities, and the relaxivity increased with the size of the magnetic nanoparticles. It was found that cellular uptake changed with both size and surface physiochemical properties, and that PVP-IO-37 with a core size of 37 nm and hydrodynamic particle size of 100 nm exhibited higher cellular uptake rate and greater distribution than other PVP-IOs and Feridex. We systematically investigated the effect of nanoparticle size on MRI of normal liver and hepatic lesions <i>in vivo</i>. The physical and chemical properties of the nanoparticles influenced their pharmacokinetic behavior, which ultimately determined their ability to accumulate in the liver. The contrast enhancement of PVP-IOs within the liver was highly dependent on the overall size of the nanoparticles, and the 100 nm PVP-IO-37 nanoparticles exhibited the greatest enhancement. These results will have implications in designing engineered nanoparticles that are optimized as MR contrast agents or for use in therapeutics. 2010-12-28 00:00:00 MR contrast agents hydrodynamic particle size nanoparticle PVP nm T 2 relaxivities hepatic lesions MRI